V. Boolean Operations

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I. Review of Student Work

II. Resource List Highlights

III. Geometric Data Types and Operations

• 2D: Line segments vs. Polylines (Grouped lines) vs. Area Polygon
• 3D: Surfaces vs. Surface Primitives (grouped surfaces) vs. Solids
• Appearance similar, possibilities different

IV. Matching CAD methods to architectural construction .

Linear elements for skeletal wood or steel members.

• Use in structural hierarchies (i.e. member > truss > flat frame > bay module).

Surface elements for sheathing or enclosure, tensile structures

• extrusion: (pulling a shape along a straight path) metal profiles and rolled steel sections.
• lathing (drawing a shape along a circular path)
• lofting or skinning (different shapes along any path): glass-blowing.

Solid elements for concrete, weight-bearing masonry and earth-sheltered design.

• Boolean operations: union, subtraction, and intersection.
• Punctured wall from a Pinos and Miralles project by Thomas Wong

V. 2D Boolean operations

TRY IT: Tutorial 24.4, Chapel Plan
If you finish early, copy the plan to Modeling and push into 3D

VI. 3D Boolean operations & Solid modeling

A. Characteristics of Solids

• Boundary rep vs. constructive solid geometry (CSG)
• Boolean operations
• Hierarchy of boolean operations
• Substitution of primitives in CSG

TRY IT: Use Boolean operations to make an Eiffel Tower by

1. opening eiffel.fmz from Session Nine of the Course Disk
2. extruding a closed A-shape to make a long bar
3. subtracting a void
4. rotating the bar 90 degrees
5. intersecting the two.

B. Pros & Cons of Solids

• Advantages: can use Boolean operations, data contains mass information
• Disadvantages: Models more complex, Can create non-sensical data

TRY IT: Vaulted Bath Building

VII. Modelling Approaches

• Top down: State of Illinois Building
• Iterative refinement: Edwin Lee's skylight for Moore Ruble Yudell's Willamette Hall
• Bottom up: Frank Lloyd Wright concrete block study

VIII. Transparency Maps

III. Assignment 5